This invention concerns in general, the manufacture of hybrid circuits, and in particular the final assembly and packaging of chip components unto substrates or chip carriers, including a novel substrate or chip carrier for one or several components, and assembly methods and equipment.
Chip assemblies can be broadly classified according to the method of interconnection between terminal pads on substrate and chip, into two general groups: wire bonding, and face bonding methods. The wire bonding group includes the wire bonding proper, wherein wires are welded to corresponding terminal pads on chip and substrate, and modified systems including beam lead chips, having extended buss leads integral with the chip element; Tab systems, or Tape Automated Bonding, which uses leads fabricated in continuous film type format. The leads are cut off after being gang bonded to the chip terminal pads. The face bonding type, also called flip-chip, because the chip is flipped over face to face with the substrate, bringing terminal pads on the chip facing corresponding terminal pads on the substrate. Local welding at the pads is achieved either by means of providing protruding terminal pads on the chip, as in the bump, pillar and pedestal bonding methods or with the aid of additional standoffs, as in the ball-soldering method.
The present invention is of the flip-chip category.
These existing systems are suffering from one or several of the following shortcomings: they are more costly to produce; they do not lend themselves readily to automating; they require additional work done to the chip component and therefore existing chips cannot be used directly; the resulting assembly is not rugged; they result in severily reduced terminal density; and, cannot be used with an unlimited number of terminals.